1. Field of the Invention
The present invention relates to hog operations, and in particular to a one-step farrow to finish hog operation, including waste management and recycling.
2. Background of the Art
The hog is a domesticated mammal belonging to the swine family and is extensively raised in almost every part of the world as a food animal. Although the term "pig" by definition refers to a young swine, it is also commonly used worldwide to refer to a male or female swine of any age. A young female swine is referred to as a gilt until the first farrow, after which the animal is referred to as a sow. Hogs are well-adapted for the production of meat because they grow and mature rapidly. Furthermore, hogs have a relatively short gestation period of about 114 days and a sow typically produces nine (9) to eleven (11) offspring with each litter.
There are more than 90 breeds of hogs recognized today, differing in growth rate, litter sizes, mature body size, and so forth. In the United States, most commercial hog production is based on crossbred animals, and the animals are grown under more intensive conditions than cattle and sheep.
The three principle types of hog operations are: Production of purebred breeding stock, production of feeder pigs, and growing and finishing of feeder pigs for sale and slaughter. Some producers have formed cooperatives and raise hogs for all three purposes, building large farrowing units where as many as 1,000 sows can give birth. After the feeder pigs are weaned, the individual members of the cooperatives typically buy them back for feeding and finishing. The confinement of so many hogs in just one farrowing unit, however, leads to problems with virus and bacteria buildup. Furthermore, each time the hog is moved, it must adjust to the bacteria in the new location, before it can continue to grow efficiently. Other operations may breed and grow hogs for all three purposes on one site, but separate the areas or buildings where farrowing, weaning, growing, and finishing take place. Again, such relocations may help to overcome the problems associated with virus and bacteria buildup, but the repeated adjustments the hog must make in each new location reduce growing efficiency, and increase labor costs as well.
In order to raise healthy and profitable hogs efficiently, care must also be given to the selection of feeds, temperature and facility size. Often the feeders themselves are difficult to keep clean, not only adding to labor costs, but increasing the chances for contamination of the feed. Newborn pigs are also very sensitive to cold, and often some type of heat is provided to warm the pigs when the temperature drops. Some conventional pig warmers, however, keep the newborn pigs at the belly of the sow where they can be pulled under and smothered or crushed when the mother pig rolls onto her belly. It is also important to ensure that pigs are kept cool enough, since they have no sweat glands, and can easily overheat in warm conditions.
Adequate ventilation is also extremely important in removing toxic gases such as ammonia and hydrogen from waste products. Inadequate ventilation can not only be deadly for the pigs, but also for humans who breathe the toxic air. One current type of ventilation system uses natural air flow which is initiated by opening the peak of the roof so that the hot air escapes through the opening, and pulls air in from the open sides. The open sides can also be closed when necessary with a suitable covering. This system works fairly well in some climates, but not in northern or extreme southern climates where temperature extremes are common. Another well-known ventilation method utilizes large fans on one end of a building for drawing air from the other end of the building through a water-cooled fibrous material. A similar system pulls air through a plastic air tube which typically extends the length of the building and has holes through which the air is blown. These types of systems work best in dry climates and on dry days when evaporation can cool the air. When the air is saturated with water during humid conditions, however, there is less evaporation, and therefore less cooling. Although more adequate cooling and movement of the air is typically achieved with the methods which use fans, all of the above-described ventilation systems allow air to flow uncontrolled throughout the building and directly onto the hogs. This problem is not reduced with the use of wire mesh panels to separate the hogs in their pens, as air easily passes through the open fencing onto the hogs. Such drafty conditions can lead to discomfort and possible ill-health for the hogs.
A proper farrowing pen is also important in providing adequate comfort for the sow, as well as comfort and safety for the newborn pigs. The use of solid concrete or heavy metal wire mesh for flooring, however, leads to problems with bacteria build-up. Specifically, bacteria can grow and multiply in the pores of the concrete and on the surface of the wire mesh. Although applying a sealant can reduce this problem to some extent in the case of concrete flooring, this only increases labor and material costs. In the case of heavy wire mesh flooring, the metal often rusts, exacerbating problems with bacteria build-up. Furthermore, the heavy wire mesh flooring itself is uncomfortable for the pigs, and the wires can cut their feet.
A farrowing pen having a heated area in the floor to attract young pigs away from their mother is taught in U.S. Pat. No. 3,181,503 to Tripp, which is hereby incorporated by reference. Other features of the farrowing pen in Tripp include a design wherein there is a separate stall within the pen having fixed partitions to restrict the sow's movement. In this way, the baby pigs still have access to the sow for nursing, but the sow cannot encroach on the young pigs' area and possibly harm them. Furthermore, the sow can relieve herself in just one area. The pen flooring in Tripp is comprised of a poured concrete flooring (covered with a metal floor plate) and removable T-irons located over gutters. The use of a T-shaped iron for grating allows excrement to be more easily pushed by the hogs through to the gutter below. It is now well-known, however, that T-irons cannot be kept clean and entirely free of contaminants, as they typically rust through from the inside after only a few months' time, even when a sealant has been applied. Tripp also teaches the use of feeders which reduce waste and encourage the young pigs to supplement their mother's milk, thus enabling pigs to be weaned sooner. Although such improvements in hog management have provided some increased comfort and better nutrition for the pigs, the problems of bacteria and virus buildup still exist, as well as continuing problems with high labor costs.
Further, current waste control methods do not always adequately manage the waste, resulting in operations which are unsanitary, smelly, and costly to operate. Some operations still simply manually push the pig waste to a desired location. Other operations, as described in Tripp, use slats (which are typically concrete or metal) in one area of the pen in an attempt to control waste by collecting it directly from the hog and allowing it to fall or be pushed by the hogs into deep pits or gutters located below. Those operations using the heavy wire mesh flooring throughout the pen also collect waste in underground pits. If the pits are too deep, however, the manure is not "digested" or decomposed quickly, leading to odor problems. Further, water is commonly added to the manure, tending to dilute the natural bacterial action which otherwise helps to decompose the manure.
Current outdoor lagoons built to handle overflow manure and to separate the solids fraction are typically several feet deep, which again results in a slowing down of the natural bacterial action. This can lead to an increase in offensive odors due to the many chemical reactions taking place in the lagoons. Such lagoons, particularly for large hog operations, are not only unpopular, but cause adverse environmental impact as well. Specifically, toxic leachates and their associated volatile organic compounds as well as offensive inorganic gases and vapors emanating from such lagoons are a major source of atmospheric pollution. Further, economically-important materials such as nitrogen and sulfur which are contained in the toxic off-gases are being wasted. It is well-known that the method in which manure is handled not only impacts the profitability of a livestock operation, but also impacts significantly on the environment, including the overall health of the livestock and caretakers.
In U.S. Pat. Nos. 3,875,319 and 4,018,899 to Seikler, et. al., a process and apparatus for recovering feed products from animal manure with the use of successive liquid and solid separation stages are taught. This complex process is a batch process in which the manure is transported to the apparatus for treatment. Water and sometimes chloride are also added to kill bacteria. Although this system is reusing manure, it does not teach any improved method for managing or recycling manure on-site at a livestock operation, as it suggests manually scraping manure from the pens.
Thus, what is needed is a sanitary, efficient, humane, and economical system in which to raise and farrow hogs, in which virus and bacteria build-up is reduced, the exposure of newborns to various bacteria and viruses is limited, and manure is adequately controlled to reduce odors and protect the environment.